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Old Feb 2, 2005, 6:55 PM   #1
sdh
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Hi all,

Please have a look at the image below. It's a full size crop of a photo ofthe Eiffel tower model some folks at my company built a few years backusing toy blocks that the HR dept gave away to promote the "employee referral program". Anyway... Notice that the text on the green and yellow blocks is sharp but it's godawful blurry on the red blocks (the blocks themselves look blurry too). Any ideas what's causing this? Im ruling out focus depthbecause there are green blocks at different distances from the camera which are all sharp whereas all the red blocks are fuzzy. It looks like the camera just does a crappy job resolving red or red/black contrast. The picture was taken with a Sony V3 set to 7MP, jpeg-fine, flash used and the subject is ~1 meter away. I saw the exact same red fuzziness when I took this picture w/ my Sony W1 also.

Would this be a problem with:these 2 specific cameras,or, Sony cameras in general,or, digital cameras in general, or, cameras in general?:? Ill try taking the same photo in RAW & TIFF modes and see if it comes out any better.
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Old Feb 2, 2005, 7:20 PM   #2
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I've never seen that. I guess it could be the JPG compression and TIFF or RAW could work. I know red is harder to focus on because of the longer wavelength, but I wouldn't think it would affect the black like that. Let us know how raw works out.

The Sony CCDs for the V1 and V3 are common in other brands, so if it is caused by the sensor I wouldn't think it a problem specific to Sony cameras.

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Old Feb 2, 2005, 8:04 PM   #3
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If this were a scanned color negative, the answer would be obvious. Color print film does a lousy job with red regardless of the brand.

I think JPEG compression may have something to do with it. Can you shoot the image in raw mode and compare the images?
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Old Feb 3, 2005, 10:42 PM   #4
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Update: I shot the same exact picture in RAW and TIFF and got the same results with both- blurry reds. I have to think that the image sensor simplydoes a poorer job resolving red than other colors. I'd be curious to know if other people get similar result w/ other cameras.

Other subject matter Ive found that duplicates this test is a rack of cds, dvds, cassettes, or books, etc. Basicallyanything withlots of various color texts over various background colors. In aphoto ofmy cd rack I found that the red on black and black on red labels were much fuzzier than other-colored labels with same-size text. Again, Im curious if other cameras do this too!
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Old Feb 4, 2005, 12:51 AM   #5
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oooh, i hate to think that might be a lense problem.
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Old Feb 4, 2005, 10:07 AM   #6
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berto wrote:
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oooh, i hate to think that might be a lense problem.
Somehow I doubt that. The basic lens technology in digital cams is pretty much the same as what's been used in film cams for decades. My point being, manufacturers understand lens design really well by now and there shouldnt be any surprises. So either "blurry reds" is a well known issue with lenses of any make (like purple fringe), or, it's not really a lens problem at all. On the other hand, image sensor technology is very much evolving and still being figured out. I bet this is a shortcoming with the image sensor, and that many other cameras (of any make)would produce similar results with a photo like this.:roll:
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Old Feb 4, 2005, 10:51 AM   #7
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We know that the V3 does increase saturation on bright Reds AND bright Greens by about 13%. This is not uncommon for digital cameras...some are much worse with reds than that. (For example, the $8,000 Canon EOS-1D Mark II is particularly noted for this but RAW processing is the accepted workaround.)

I haven't noticed this with any of my V3 shots.

Can you post the EXIF data on the shot?

What lighting were you using? The shadows look as if the flash was to theright of the lens (since the shadows are on the left). The built-in flash (or a flash attached to the hotshoe)is positioned (more or less) directly above the lens.

In any case, you have three saturation settings on the V3 (' + ' ,'Normal' and '- ') check and see if changing these settings might help the problem? (Page 137 in the manual)
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Old Feb 4, 2005, 11:50 AM   #8
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I did some test shots and I DID find a bright red that DOES oversaturate to the extent that your initial shots show. Other reds did not have the problem so, it is likely just one of those particular shades that gives a lot of trouble to certain cameras. As I noted, it is not an unheard of problem and, because it is specific to this shade of red, should not effect the majority of users...so long as they don't specialize in photographs of Santa Claus! :-)
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Old Feb 4, 2005, 12:26 PM   #9
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I had a similar problem with a photo of a audio recorder. The photo was perfect except that the red record button looked wierd. Taken with an Olympus E-1 the red button had odd patterning (RAW or JPG) but the same thing taken with my 20D did not show the problem.
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Old Feb 4, 2005, 2:22 PM   #10
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Meryl Arbing wrote:
Quote:
Can you post the EXIF data on the shot?

What lighting were you using? The shadows look as if the flash was to theright of the lens (since the shadows are on the left). The built-in flash (or a flash attached to the hotshoe)is positioned (more or less) directly above the lens.

In any case, you have three saturation settings on the V3 (' + ' ,'Normal' and '- ') check and see if changing these settings might help the problem? (Page 137 in the manual)
Meryl, here's the EXIF:

focal len = 7.0mm, 1/40 sec, F2.8, Program AE @ 0EV, ISO 100, auto WB, contrast, saturation & sharpness all at default setting.

The V3's internal flash was used w/ no external flash. Ambient light was your average office-brightness flourescent lighting.

I tried reprocessing the RAW image, turning saturation down some, then some more, then waaaayyy down until the image was all grey, and saving to TIFF w/each setting. I assume this is essentially the same as turning the saturation down in-camera when shooting in TIF or JPG, yes? Still, in every image, the text over the red blocks is fuzzier than the others.

Note that Idid this processing Sony's image converter (I dont have PS), which presumably uses a similarconversionalgorithm as inside the camera.

Are we able to determine whether the culprit here is Sony's conversion algorithm or the image sensor itself?
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